Oilpan: Prepare to make ExecutionContext GarbageCollectedMixin.

Source/platform/heap/Handle.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef Handle_h
 #define Handle_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/ThreadState.h"
 #include "platform/heap/Visitor.h"
+#include "wtf/Functional.h"
 #include "wtf/HashFunctions.h"
 #include "wtf/Locker.h"
 #include "wtf/RawPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/TypeTraits.h"
 
 namespace WebCore {
 
 template<typename T> class HeapTerminatedArray;
 
@@ skipping 1098 matching lines @@
 };
 
 template<typename T, size_t inlineCapacity>
 struct NeedsTracing<ListHashSetNode<T, WebCore::HeapListHashSetAllocator<T, inlineCapacity> > *> {
     // All heap allocated node pointers need visiting to keep the nodes alive,
     // regardless of whether they contain pointers to other heap allocated
     // objects.
     static const bool value = true;
 };
 
+// For wtf/Functional.h
+template<typename T, bool isGarbageCollected> struct PointerParamStorageTraits;
+
+template<typename T> struct PointerParamStorageTraits<T*, false> {
+    typedef T* StorageType;
+
+    static StorageType wrap(T* value) { return value; }
+    static T* unwrap(const StorageType& value) { return value; }
+};
+
+template<typename T> struct PointerParamStorageTraits<T*, true> {
+    typedef WebCore::CrossThreadPersistent<T> StorageType;
+
+    static StorageType wrap(T* value) { return value; }
+    static T* unwrap(const StorageType& value) { return value.get(); }
+};
+
+// FIXME: This doesn't support collections and const types. See
+// COMPILE_ASSERT_IS_GARBAGE_COLLECTED.
+template<typename T> struct ParamStorageTraits<T*> : public PointerParamStorageTraits<T*, WTF::IsSubclassOfTemplate<T, WebCore::GarbageCollected>::value || WebCore::IsGarbageCollectedMixin<T>::value> {
+};
+
+// We assume RawPtr<T> is used only for garbage-collected types.
+template<typename T> struct ParamStorageTraits<RawPtr<T> > {
+    typedef WebCore::CrossThreadPersistent<T> StorageType;
+
+    static StorageType wrap(RawPtr<T> value) { return value.get(); }
+    static T* unwrap(const StorageType& value) { return value.get(); }
+};
+
 } // namespace WTF
 
 #endif